Transport systems which are suitable for use on ships for door-to-door transport of cargo holders typically take one of two forms. The first form, shown in FIG. 1, is a roll-on/roll-off type of system I in which haulage vehicles transport containers A.sup.I between the shore and the cargo decks C.sup.I of ships. These containers A.sup.I are in the form of trailers having wheels B.sup.I fixed thereon and bearing against the floor thereof. The other form of transport system is a container system II which consists of closeable cargo holders A.sup.II which are transferred between the shore and ship by means of loading cranes which are either located on the shore or on board the ship. In this system, shown in FIG. 2, the containers are designed to be stacked one on top of the other in the cargo spaces of a ship or on deck during transport.
In most circumstances, the roll-on/roll-off system I is preferred since it permits quicker door-to-door transport of the goods in the containers A.sup.I because only haulage vehicles have to be coupled to the trailers assembled on board the ship. On the other hand, the cargo holders A.sup.II of the container system II have to be loaded by cranes at the receiving port onto special wheeled haulage trucks in order to be driven to the intended destination on land after unloading. The use of transport system I, however, is expensive since large dead spaces are formed between the trailers when they are loaded onto the ship. Moreover, the ships on which transport system I is used are not as quick as the larger existing container freight vessels on, for example, Atlantic crossings. Furthermore, Ro-Ro vessels have expensive and complex ventilation systems because of the exhaust fumes from the haulage vehicles, and special complex and expensive ramp systems are required for loading and unloading these vessels.
There thus exists a need for a transport system which provides the ease of loading and unloading and quick delivery associated with the roll-on/roll-off system I, but which may be stacked in close arrangement for transport on a ship.